On the standards track: Yes
Is Experimental: No
Is Deprecated: No
In Chrome version 29 on 2013-08-20
In Chrome Android version 29 on 2013-08-21
In Edge version 12 on 2015-07-29
In Firefox version 20 on 2013-04-02 Note: Firefox 28 added multi-line flexbox support.
In Firefox for Android version 20 on 2013-04-02 Note: Firefox for Android 28 added multi-line flexbox support.
In Internet Explorer version 11 on 2013-10-17 Note: IE incorrectly positions inline block content inside flex containers. See the discussion on Microsoft Answers. IE incorrectly positions inline block content inside flex containers. See the discussion on Microsoft Answers.
In Quest Browser version 5.0 on undefined
In Opera version 16 on 2013-08-27
In Opera Android version 16 on 2013-09-18
In Safari version 9 on 2015-09-30
In Safari on iOS version 9 on 2015-09-16
In Samsung Internet version 2.0 on 2014-10-17
In WebView Android version 4.4 on 2013-12-09
In WebView on iOS version 9 on 2015-09-16